A milliohm meter is a very handy piece of test equipment. Most hand-held multimeters cannot measure low resistances and bench meters that can, are usually quite expensive. [barbouri] has shared details of his milliohm meter build on his blog post, and it looks pretty nice.
I need a DAC for my AKG K702. However, the more I looked at commercially available a.k.a. “audiophile” products, the more snake oil I smell. So even before I ordered my CEntrance DACPort Slim, I was already looking into how I can reinventing the wheel
I use OSHPark for prototyping PCBs. I decided to use their 4-layer FR-408 stackup simply for an un-broken ground layer. Turns out that the analog signals can easily fit on the top layer, so I allocated the power layer to the negative rail, and the bottom layer to positive rails.
The DAC + Filter module works! It produces reasonably clean line-level audio signal as expected.
Kevin H. Patterson designed this solution for trailer light wiring after installing a towing hitch on his vehicle:
This is a power module designed to control trailer lights based on signals from your vehicle’s lighting circuits. Most vehicles have at least 4 separate circuits: Running (Tail) Lights, Brake, Left Turn, and Right Turn. Most basic trailers have a 4-wire connector with only 3 signals: Running (Tail) Lights, Left Turn, and Right Turn. The trailer does not have a separate circuit for Brake lights; applying the Brake is supposed to light up both the Left and Right Turn signals together.
The board can be purchased on Tindie:
4-Line to 3-Line Combining Tail Light Power Module for 12V Systems
If you’re making a circuit that is designed to plug into a breadboard, you have a problem. Those 0.1″ header pins are square, and the metal leaf contacts inside a solderless breadboard will eventually get bent out of shape. You only need to look at the breadboards in a university electronics lab for evidence of…
thingSoC is an Open Source socket system for IoT development and has just launched a new Crowdy Supply campaign:
Build any IoT or Networked device you can imagine!
The thingSoC Grovey! platform gives you the freedom to choose from hundreds of existing sensors, actuators, and radios to quickly create new electronic systems, in plug together configurations that were not possible before. Easily mix together different CPUs, Radios, and Peripherals, like Servos, Motors, Relays, Sound and Lights, and then program them in your choice of Integrated Development Environments (IDE).
The thingSoC Grovey Series files are available on GitHub:
- TSOC_Teensy3x: Teensy3.x Adapter for the Grove System
- TSOC_GROVEY_ONE: Model “Uno” Arduino Clone for the Grove System
- TSOC_GROVEY_FOUR: Model “Four” PSoC4 mini for the Grove System
- TSOC_GROVEY_WIFI: ESP8266 Wi-Fi Adapter for the Grove System
- TSOC_GROVEY_I2CHUB: I2C Hub/Switch for the Grove System
- TSOC_GROVEY_GPIO: SX1509 GPIO for the Grove System
- TSOC_GROVEY_UART: USB to UART for the Grove System
We are always surprised how much useful hacking gear is in the typical craft store. You just have to think outside the box. Need a hot air gun? Think embossing tool. A soldering iron? Check the stained glass section. Magnification gear? Sewing department. We’ve figured out that people who deal with beads use lots of fine…
From the Hackaday blog:
Building a software defined radio (SDR) involves many trades offs. But one of the most fundamental is should you use an FPGA or a CPU to do the processing. Of course, if you are piping data to a PC, the answer is probably a CPU. But if you are doing the whole system, it is a vexing choice.
The FPGA can handle lots of data all at one time but is somewhat more difficult to develop and modify. CPUs using software are flexible–especially for coding user interfaces, networking connections, and the like) but don’t always have enough horsepower to cope with signal processing tasks (and, yes, it depends on the CPU).
[Eric Brombaugh] sidestepped that trade off. He used a board with both an ARM processor and an ICE FPGA at the heart of his SDR design. He uses three custom boards: one is the CPU/FPGA board, another is a 10-bit converter that can sample at 40 MSPS (sufficient to decode to 20 MHz), and an I2S DAC to produce audio. Each board has its own page linked from the main project.Z
The iceRadio project page has additional details:
- RXADC Board – 40MSPS 10-bit ADC for capturing HF-band RF signals.
- STM32F303 and ice5 Board – MCU and FPGA which implement the digital receiver.
- I2S DAC PMOD – Used for stereo audio output of demodulated signals.
Design files and source code are available on GitHub:
SKiDL is very, very cool. It’s a bit of Python code that outputs a circuit netlist for KiCAD. Why is this cool? If you design a PCB in KiCAD, you go through three steps: draw the schematic, assign footprints to the symbolic parts, and then place them. The netlist ties all of these phases together […]
The source code is available on GitHub:
FacelessTech designed this small board to act as a surface-mount edge connector:
So you want to joint two boards together, You decide to use through hole female and male 2.54 pitch headers. Normally you would use through hole than ether have a 90 degree headers or just bend them over. For years this is how I did it, I would have to make sure I made sure the holes were just the right distance from the edge of the board.
The KiCad design files are available on GitHub: